[esp-r] Re: Regarding thermal and optical properties of construction materials

[Achim Geissler]

Hi Satya

each material has an assigned reflectivity and IR emissivity. For a multi-layered construction, however, only the outermost values (inside and outside faces of the construction) are relevant for the simulation.

Best
Achim



On May 9, 2013, at 1:32 AM, Satya <ringo.satyarr at gmail.com> wrote:

> Can I run the simulation by assigning IR emissivity and solar absorptivity to materials located deep inside a construction? Like brick?
> 
> 
> On Wed, May 8, 2013 at 4:59 PM, Jon Hand <jon at esru.strath.ac.uk> wrote:
> 
> The issue of paint mentioned below.  There are several examples of applying paint or a coating
> to materials. - there are several types of concrete which are identical except for
> the surface properties  - white painted and stone colour.  Or Steel and Beige painted steel and White painted steel.
> 
> This approach is based on the assumption that the thin layer only makes a tiny impact on the conductivity
> density and specific heat of the material.
> 
> I would advise against treating a paint layer as transparent.  Seems overly complex and
> getting the optical data would be a challenge.
> 
> Surface solar absorption and emissivity is sometimes based on approximate information in
> the literature of building simulation.  It is possible to measure, few people do this.
> 
> Regards, Jon Hand
> ________________________________________
> From: esp-r-bounces at lists.strath.ac.uk [esp-r-bounces at lists.strath.ac.uk] On Behalf Of Satya [ringo.satyarr at gmail.com]
> Sent: 08 May 2013 09:18
> To: ESP-r Users' Club
> Subject: [esp-r] Regarding thermal and optical properties of construction       materials
> 
>  Hi
> 
> 1. Thermal properties:
> 
>  I have a list of building materials used for the building I am trying to model. Unfortunately, none of these materials are listed in the ESP-r library. Where can I find the relevant properties of those materials which ESP-r needs to run a simulation? Here is the list of the materials.
> 
> _________________________________________
> 
> 1 : 1.67 : 2.84 reinforced concrete (C:S:A)
> 
> 1:4 cement mortar plaster
> 
> 1:4 cement sand plaster
> 
> vitrified tiles
> 
> typical values for fiberglass reinforced plastic
> 
> typical values for ply
> 
> typical values for brickbat
> 
> _________________________________________
> 
> 
> 
> 2. Optical properties
> 
>  The library doesn't include layers of paint. I intend to create a new material by assigning the following properties:
> 
> conductivity: infinite // is this allowed
> 
> density: 0 // is this allowed
> 
> specific heat: same as that of underlying plaster
> 
> 
> 
> But how do I estimate IR emissivity and solar absorptivity? The internal paint is a white and external is grey. Is there an easy way to measure it or are there typical values for paints depending on the colour? Where do I find this data?
> 
>  It also occurred to me that the paint layer, being very thin, could be modelled as a transparent construction because my guess is that it does let light pass through because of how thin it is. However, for this I will need to find 8 optical properties of paint (3 types of transmittances, 4 types of reflectences and colour rendering).
> 
> I understand that this is more accurate but if anybody tells me that an opaque material type paint won't lead to major inaccuracies, I will gladly work with an opaque paint.
> 
>  Where do I find the detailed optical data of 'white emulsion paint' and 'grey emulsion paint’?
> 
>  Thanks,
> 
> Satya
> 
> 
> _______________________________________________
> esp-r mailing list
> esp-r at lists.strath.ac.uk
> http://lists.strath.ac.uk/mailman/listinfo/esp-r

achim.geissler at intergga.ch




-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.strath.ac.uk/archives/esp-r/attachments/20130509/72cf2730/attachment.html